Air filter grill



FIG. 1 is a rear perspective view from the left side of the air filter grill;

FIG. 2 is a front perspective view from the left side; and,

FIG. 3 is a top view.

The broken line showing of the air filter in all of the FIGURES is for illustrative purposes only as to where the grill is positioned and forms no part of the claimed design. 

The ornamental design for an "air filter grill", as shown and described. 